My old Acoustic Research AR 9 speakers sounded great in the 1980s. But they need some work now. The old Callins capacitors are shot. I'm fortunate I found a local guy who specializes in rebuilding/refurbishing Polk Audio speakers and is willing to give my AR 9 a look.
We have the crossover schematics and he is going to replicate the crossover but using modern better performing capacitors and resistors while using the original inductors and replacing the old crappy PVC jacketed wiring with something better.
I'm also going to ask him to take out the response switches from the signal path and leave them at "0". I never used them anyway, so figure why not take them out for a cleaner electrical path.
When he is done, I expect the performance of the speakers to be as good as new or even better. That this can be done to speakers that are 46 years old for a reasonable price is amazing. This is going to cost me around $2000 or so. I could never buy any $2000/pair speaker today that would give me as much value.
How good is the crossover in your loudspeakers?
I just watched a Danny Richie YouTube video from three weeks ago (linked below). Danny is the owner/designer of GR Research, a company that caters to the DIY loudspeaker community. He designs and sells kits that contain the drivers and crossover schematics to his loudspeakers, to hi-fi enthusiasts who are willing and able to build their own enclosures (though he also has a few cabinet makers who will do it for you if you are willing to pay them to do so).
Danny has also designed crossovers for loudspeaker companies who lack his crossover design knowledge. In addition, he offers a service to consumers who, while liking some aspects of the sound of their loudspeakers, find some degree of fault in those loudspeakers, faults Danny offers to try to eliminate. Send Danny one of your loudspeakers, and he will free of charge do a complete evaluation of it's design. If his evaluation reveals design faults (almost always crossover related) he is able to cure, he offers a crossover upgrade kit as a product.
Some make the case that Danny will of course find fault in the designs of others, in an attempt to sell you one of his loudspeaker kits. A reasonable accusation, were it not for the fact that---for instance---in this particular video (an examination of an Eggleston model) Danny makes Eggleston an offer to drop into the company headquarters and help them correct the glaring faults he found in the crossover design of the Eggleston loudspeaker a customer sent him.
Even if you are skeptical---ESPECIALLY if you are---why not give the video a viewing? Like the loudspeaker evaluation, it's free.
https://youtu.be/1wF-DEEXv64?si=tmd6JI3DFBq8GAjK&t=1
And for owners of other loudspeakers, there are a number of other GR Research videos in which other models are evaluated.